Annotation of embedaddon/sudo/common/event_poll.c, revision 1.1
1.1 ! misho 1: /*
! 2: * Copyright (c) 2013 Todd C. Miller <Todd.Miller@courtesan.com>
! 3: *
! 4: * Permission to use, copy, modify, and distribute this software for any
! 5: * purpose with or without fee is hereby granted, provided that the above
! 6: * copyright notice and this permission notice appear in all copies.
! 7: *
! 8: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
! 9: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
! 10: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
! 11: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
! 12: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
! 13: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
! 14: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
! 15: */
! 16:
! 17: #include <config.h>
! 18:
! 19: #include <sys/types.h>
! 20: #include <sys/time.h>
! 21: #include <stdio.h>
! 22: #ifdef STDC_HEADERS
! 23: # include <stdlib.h>
! 24: # include <stddef.h>
! 25: #else
! 26: # ifdef HAVE_STDLIB_H
! 27: # include <stdlib.h>
! 28: # endif
! 29: #endif /* STDC_HEADERS */
! 30: #ifdef HAVE_STDBOOL_H
! 31: # include <stdbool.h>
! 32: #else
! 33: # include "compat/stdbool.h"
! 34: #endif /* HAVE_STDBOOL_H */
! 35: #ifdef HAVE_STRING_H
! 36: # include <string.h>
! 37: #endif /* HAVE_STRING_H */
! 38: #ifdef HAVE_STRINGS_H
! 39: # include <strings.h>
! 40: #endif /* HAVE_STRINGS_H */
! 41: #ifdef HAVE_UNISTD_H
! 42: # include <unistd.h>
! 43: #endif /* HAVE_UNISTD_H */
! 44: #include <errno.h>
! 45: #include <poll.h>
! 46:
! 47: #include "missing.h"
! 48: #include "alloc.h"
! 49: #include "fatal.h"
! 50: #include "sudo_debug.h"
! 51: #include "sudo_event.h"
! 52:
! 53: /* XXX - use non-exiting allocators? */
! 54:
! 55: int
! 56: sudo_ev_base_alloc_impl(struct sudo_event_base *base)
! 57: {
! 58: int i;
! 59: debug_decl(sudo_ev_base_alloc_impl, SUDO_DEBUG_EVENT)
! 60:
! 61: base->pfd_high = -1;
! 62: base->pfd_max = 32;
! 63: base->pfds = erealloc3(NULL, base->pfd_max, sizeof(struct pollfd));
! 64: for (i = 0; i < base->pfd_max; i++) {
! 65: base->pfds[i].fd = -1;
! 66: }
! 67:
! 68: debug_return_int(0);
! 69: }
! 70:
! 71: void
! 72: sudo_ev_base_free_impl(struct sudo_event_base *base)
! 73: {
! 74: debug_decl(sudo_ev_base_free_impl, SUDO_DEBUG_EVENT)
! 75: efree(base->pfds);
! 76: debug_return;
! 77: }
! 78:
! 79: int
! 80: sudo_ev_add_impl(struct sudo_event_base *base, struct sudo_event *ev)
! 81: {
! 82: struct pollfd *pfd;
! 83: debug_decl(sudo_ev_add_impl, SUDO_DEBUG_EVENT)
! 84:
! 85: /* If out of space in pfds array, realloc. */
! 86: if (base->pfd_free == base->pfd_max) {
! 87: int i;
! 88: base->pfd_max <<= 1;
! 89: base->pfds =
! 90: erealloc3(base->pfds, base->pfd_max, sizeof(struct pollfd));
! 91: for (i = base->pfd_free; i < base->pfd_max; i++) {
! 92: base->pfds[i].fd = -1;
! 93: }
! 94: }
! 95:
! 96: /* Fill in pfd entry. */
! 97: ev->pfd_idx = base->pfd_free;
! 98: pfd = &base->pfds[ev->pfd_idx];
! 99: pfd->fd = ev->fd;
! 100: pfd->events = 0;
! 101: if (ISSET(ev->events, SUDO_EV_READ))
! 102: pfd->events |= POLLIN;
! 103: if (ISSET(ev->events, SUDO_EV_WRITE))
! 104: pfd->events |= POLLOUT;
! 105:
! 106: /* Update pfd_high and pfd_free. */
! 107: if (ev->pfd_idx > base->pfd_high)
! 108: base->pfd_high = ev->pfd_idx;
! 109: for (;;) {
! 110: if (++base->pfd_free == base->pfd_max)
! 111: break;
! 112: if (base->pfds[base->pfd_free].fd == -1)
! 113: break;
! 114: }
! 115:
! 116: debug_return_int(0);
! 117: }
! 118:
! 119: int
! 120: sudo_ev_del_impl(struct sudo_event_base *base, struct sudo_event *ev)
! 121: {
! 122: debug_decl(sudo_ev_del_impl, SUDO_DEBUG_EVENT)
! 123:
! 124: /* Mark pfd entry unused, add to free list and adjust high slot. */
! 125: base->pfds[ev->pfd_idx].fd = -1;
! 126: if (ev->pfd_idx < base->pfd_free)
! 127: base->pfd_free = ev->pfd_idx;
! 128: while (base->pfd_high >= 0 && base->pfds[base->pfd_high].fd == -1)
! 129: base->pfd_high--;
! 130:
! 131: debug_return_int(0);
! 132: }
! 133:
! 134: int
! 135: sudo_ev_scan_impl(struct sudo_event_base *base, int flags)
! 136: {
! 137: struct sudo_event *ev;
! 138: int nready, timeout;
! 139: struct timeval now;
! 140: debug_decl(sudo_ev_scan_impl, SUDO_DEBUG_EVENT)
! 141:
! 142: if ((ev = TAILQ_FIRST(&base->timeouts)) != NULL) {
! 143: struct timeval *timo = &ev->timeout;
! 144: gettimeofday(&now, NULL);
! 145: timeout = ((timo->tv_sec - now.tv_sec) * 1000) +
! 146: ((timo->tv_usec - now.tv_usec) / 1000);
! 147: if (timeout <= 0)
! 148: timeout = 0;
! 149: } else {
! 150: timeout = (flags & SUDO_EVLOOP_NONBLOCK) ? 0 : -1;
! 151: }
! 152:
! 153: nready = poll(base->pfds, base->pfd_high + 1, timeout);
! 154: sudo_debug_printf(SUDO_DEBUG_INFO, "%s: %d fds ready", __func__, nready);
! 155: switch (nready) {
! 156: case -1:
! 157: /* Error or interrupted by signal. */
! 158: debug_return_int(-1);
! 159: case 0:
! 160: /* Front end will activate timeout events. */
! 161: break;
! 162: default:
! 163: /* Activate each I/O event that fired. */
! 164: TAILQ_FOREACH(ev, &base->events, entries) {
! 165: if (ev->pfd_idx != -1 && base->pfds[ev->pfd_idx].revents) {
! 166: int what = 0;
! 167: if (base->pfds[ev->pfd_idx].revents & (POLLIN|POLLHUP|POLLNVAL|POLLERR))
! 168: what |= (ev->events & SUDO_EV_READ);
! 169: if (base->pfds[ev->pfd_idx].revents & (POLLOUT|POLLHUP|POLLNVAL|POLLERR))
! 170: what |= (ev->events & SUDO_EV_WRITE);
! 171: /* Make event active. */
! 172: sudo_debug_printf(SUDO_DEBUG_DEBUG,
! 173: "%s: polled fd %d, events %d, activating %p",
! 174: __func__, ev->fd, what, ev);
! 175: ev->revents = what;
! 176: TAILQ_INSERT_TAIL(&base->active, ev, active_entries);
! 177: SET(ev->flags, SUDO_EVQ_ACTIVE);
! 178: }
! 179: }
! 180: break;
! 181: }
! 182: debug_return_int(nready);
! 183: }
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